What Is A C02 Extinguisher?

Carbon Dioxide extinguishers are filled with non-flammable carbon dioxide gas under extreme pressure. You can recognize a CO2 extinguisher by its hard horn and lack of pressure gauge. The pressure in the cylinder is so great that when you use one of these extinguishers, bits of dry ice may shoot out the horn.

CO2 Extinguishers are designed for Class B and C (flammable liquid and electrical) fires only.

What Do C02 Extinguishers Look Like?

CO2 cylinders are red and range in size from 5 lbs to 100 lbs or larger. In the larger sizes, the hard horn will be located on the end of a long, flexible hose.

How Do C02 Extinguishers Work?

Carbon dioxide extinguishes work by displacing oxygen, or taking away the oxygen element of the fire triangle. The carbon dioxide is also very cold as it comes out of the extinguisher, so it cools the fuel as well. CO2s may be ineffective at extinguishing Class A fires because they may not be able to displace enough oxygen to successfully put the fire out. Class A materials may also smolder and re-ignite.

CO2s will frequently be found in:

• Laboratories

• Mechanical Rooms

• Kitchens

• Flammable Liquid Storage Areas

How Do Dry Powder Fire Extinguishers Work?

Dry Powder Extinguishers extinguish the fire by separating the fuel from the oxygen element or by removing the heat element of the fire triangle. However, dry powder extinguishers are for Class D or combustible metal fires, only. They are ineffective on all other classes of fires.

Safe on live electrical equipment, although does not penetrate the spaces in equipment easily and the fire may re-ignite. This type of extinguisher does not cool the fire very well and care should be taken that the fire does not flare up again. Smoldering material in deep seated fires such as upholstery or bedding can cause the fire to start up again. Do not use on domestic chip or fat pan fires.There is danger of inhalation if powder extinguishers are used within buildings.

Similarly to almost all extinguishing agents the powders acts as a thermal ballast making the flames too cool for the chemical reactions to continue. Some powders also provide a minor chemical inhibition, although this effect is relatively weak. These powders thus provide rapid knockdown of flame fronts, but may not keep the fire suppressed.

How Do I Use A Dry Powder Fire Extinguisher?

Point the jet or discharge horn at the base of the flames and, with a rapid sweeping motion, drive the fire towards the far edge until all the flames are out. If the extinguisher has a hand control, wait until the air clears and if you can still see the flames, attack the fire again.

How Do Foam Fire Extinguishers Work?

Foam Fire Extinguishers are mainly water based, with a foaming agent so that the foam can float on top of the burning liquid and break the interaction between the flames and the fuel surface.

Foam agents also separate the oxygen element from the other elements.

They should not be used on Class B or C fires. The discharge stream could spread the flammable liquid in a Class B fire or could create a shock hazard on a Class C fire.

What Are Foam Fire Extinguishers Best Used For?

Fires involving solids and burning liquids, such as paint and petroleum but not suitable for chip or fat pan fires. Safe on fires caused by electricity if tested to 35kV (dielectric test) and a 1m safety distance is adhered to.

How Do I Use a Foam Fire Extinguisher?

For fires involving solids, point the jet at the base of the flames and keep it moving across the area of the fire. Ensure that all areas of the fire are out. For fires involving liquids, do not aim the jet straight into the liquid. Where the liquid on fire is in a container, point the jet at the inside edge of the container or on a nearby surface above the burning liquid. Allow the foam to build up and flow across the liquid.

How Do Wet Chemical Extinguishers Work?

A Wet Chemical Extinguiser extinguishes the fire by removing the heat of the fire triangle and prevents re-ignition by creating a barrier between the oxygen and fuel elements.

Wet chemical of Class K extinguishers were developed for modern, high efficiency deep fat fryers in commercial cooking operations. Some may also be used on Class A fires in commercial kitchens.

Most class K extinguishers contain a solution of potassium acetate, sometimes with some potassium citrate or potassium bicarbonate. The extinguishers spray the agent out as a fine mist. The mist acts to cool the flame front, while the potassium salts saponify the surface of the burning cooking oil, producing a layer of foam over the surface. This solution thus provides a similar blanketing effect to a foam extinguisher, but with a greater cooling effect. The saponification only works on animal fats and vegetable oils, so most class K extinguishers cannot be used for class B fires. The misting also helps to prevent splashing the blazing oil.

Tests have established that a 6 litre wet chemical fire extinguisher with a 75F rating can deal with a fat fire of maximum 0.11 m2 surface area.

What Are Foam Fire Extinguishers Best Used For?

Wet chemical fire extinguishers are ideal for Class K fires, involving cooking oils and fats, such as lard, olive oil, sunflower oil, maize oil and butter.

How Do I Use a Foam Fire Extinguisher?

Apply the wet chemical using the extended applicator in slow circular movements, which give a gentle, yet highly effective application. Apply the fine spray onto the burning fat until the surface of the burning cooking oil changes into a soapy like substance which prevents re-ignition. The gentle application helps to prevent burning oil splashing out of the container. Make sure that you empty the entire content of the wet chemical extinguisher onto the oil/fat, as the fire can re-ignite otherwise.

How Do Fire Blankets Work?

A Fire Blanket is a highly flame-resistant blanket that can be used to either extinguish a small fire or to wrap around a person. They are made from 2 layers of woven glass fibre fabric and an inner layer of fire retardant film. They work by cutting off the oxygen supply (oxygen is one of the three elements that a fire needs to burn) and smothering the fire.

Ensure that everyone knows where the fire blanket is stored and knows how to remove the blanket from its canister, should you ever need it. It is also mandatory that an identification sign is displayed alongside the blanket.

What Are Fire Blankets Best Used For?

Fires involving both solids and liquids. Particularly good for small clothing fires and for chip and fat pan fires providing the blanket completely covers the fire.

How Do I Use a Fire Blanket?

Place carefully over the fire. Keep your hands shielded from the fire. Do not waft the fire towards you.